Electroluminescent devices including organic thin films have been developed. Typically, electroluminescent devices each including an organic thin film, i.e., organic electroluminescent devices, each have an anode, a cathode, and an organic layer including at least a light-emitting layer and provided between the electrodes, on a substrate. The organic layer may include a hole-injection layer, a hole-transport layer, a hole-inhibition layer, an electron-transport layer, an electron-injection layer, and the like in addition to the light-emitting layer. Typically, organic electroluminescent devices each include these layers stacked on top of one another. Hitherto, organic electroluminescent devices have utilized fluorescent emission. To increase light-emission efficiency of devices, attempts have been made to utilize phosphorescent emission instead of fluorescent emission. So far, however, even if phosphorescent emission has been utilized, sufficient light-emission efficiency, luminance, and lifetime have not been obtained.
In order to increase the solubility of polyaniline, which is a conductive polymer, Patent Document 1 discloses Polymer Compound (C-1) shown below.

However, polymer materials such as Compound (C-1) have disadvantages as follows:
it is difficult to control the degree of polymerization and molecular-weight distribution of a polymer materials;
degradation due to terminal residues occurs during continuous driving; and
impurities are contained therein because the materials are difficult to purify.
To induce charge transportability in Compound (C-1), it is necessary to dope a protonic acid after oxidation. It is speculated that Compound (C-1) as a charge-transporting material for an organic electroluminescent device has disadvantages because the doped protonic acid and counter anions may diffuse.
Patent Document 1 discloses Compound (C-2) shown below as a model compound of Compound (C-1).

However, Compound (C-2) has secondary amine moieties and thus has inferior heat resistance and a poor amorphous nature. Hence, an organic thin film containing Compound (C-2) has disadvantages in that the film readily deteriorates due to crystallization, aggregation, and the like. Furthermore, Compound (C-2) disadvantageously has inferior charge transportability because the HOMO is localized at the secondary amine moieties.
Patent Document 1 proposes that Compound (C-3) be used as a charge-transporting material for an electrophotographic photoreceptor.

However, compounds such as Compound (C-3) have low heat resistance because each of the groups bonded to the nitrogen atoms of the 1,3-dihydroimidazol-2-one ring has only a single aromatic ring. Thus, compounds such as Compound (C-3) may be disadvantageous when the compounds are used as the charge-transporting materials for organic electroluminescent devices.
Accordingly, it is desirable to provide a material having an excellent ability to transport charges in addition to excellent heat resistance and an excellent amorphous nature.
[Patent Document 1] Japanese Unexamined Patent Application Publication No. 10-246973
[Non-Patent Document 1] Macromolecules 2003, 36, p.p. 4368-4373